1. Field of the Invention
This invention generally relates to an automatic flashing system suitable for use in a photographic camera, and, in particular, to an auto-flash photographing system for taking photographs with an automatically controlled flashing operation.
2. Description of the Prior Art
An auto-flash photographic camera is well knnown in the art, and it has an advantage of allowing to carry out a photographic operation under an optimal exposure condition even in a dark place. However, there is a premise for this advantage in that the amount of light required for auto-flash photography must be equal to or less than the maximum amount of light which can be supplied by a flashbulb of an auto-flashing unit, or the amount of light corresponding to a guide number in a particular setting. For this reason, if the subject to be photographed is located too far away or the stop value is set too large, underexposure will result. It is true that such an undesired situation could be avoided to some extent by moving closer to the subject to be photographed and/or setting the stop smaller in value; however, this would then limit the freedom or flexibility in taking pictures, which is sometimes quite important. In addition, it is not always possible to come closer to the subject of interest, and there are those cases where the stop value cannot be set lower in relation to a particular depth of field and/or depth of focus.